Folic acid is a vitamin required for normal growth. It was discovered as a stable factor in extracts of yeast and of liver, which cured anaemia in pregnant women. The preponderant forms of folic acid in tissues are tetrahydrofolate polyglutamates with single carbon adducts corresponding to methanol, formaldehyde and formate. Folates are essential for the enzymatic oxidation, reduction and transfer of single carbon units involved in the metabolism of thymidylate, purine nucleotides, methionine, serine, histidine and choline.

Keywords: Folates; vitamins; metabolism

Figure 1.

Folic acid

Figure 2.

5,6,7,8‐Tetrahydrofolic acid R=H

Figure 3.

5,6,7,8‐Tetrahydrofolic acid poly‐γ‐glutamate

Figure 4.

The thymidylate cycle.

Figure 5.

(a) Formation of 5‐methyltetrahydrofolate catalysed by methylenetetrahydrofolate reductase. (b) Formation of methionine catalysed by cobalamin‐dependent methionine synthase.

Figure 6.

Folate‐dependent reactions in purine nucleotide biosynthesis.

Figure 7.

Folate antagonists.

Figure 8.


Figure 9.




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Kisliuk, Roy L(Apr 2006) Folates. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0003924]